The present invention relates to a bobbin and especially to a bobbin wound with a yarn.
In order to supply yarns and especially sewing and embroidery threads, which are preferably present as smooth yarns and especially as multifilament yarns of polyester (polyethylene terephthalate), polyamide 6, polyamide 6.6 and/or mixed yarns of the afore-mentioned synthetic fibers with natural fibers, and which have the structure of doubled, twisted or cabled yarns, to the corresponding sewing or embroidery machines as part of the processing in the garment industry, it is known to wind these sewing or embroidery threads onto bobbins (packages, spools), generally designated as spools having a base (king spools), and use them accordingly.
The previously described known bobbins for receiving yarn supply have a winding zone for the yarn where the relevant yarn is then wound onto the shell of this winding zone especially as a cross-wound precision winding. Furthermore, the known bobbin is provided with a standing area (base-area) so that the bobbin can be used and stored vertically and therefore standing upright during and after usage.
Since the winding zone of the known bobbin is embodied as a cylindrical core, the problem frequently arises that, as a result of their relatively smooth surface, the highly twisted or doubled multifilament yarns wound on the shell (casing) of the winding zone possess poor positional adhesion with the result that during usage of the known bobbin, the outer yarn layers become displaced relative to the layers located thereunder. This layer fall-off can result in a partial or complete overlapping of the outer yarn layers by the inner yarn layers. This in turn prevents the yarn from being drawn off from the king spool with uniform tension and further results in a jerkily draw-off of the loosened and entangled yarns which ultimately causes a thread break and therefore considerable disturbance of production during sewing or embroidery.